         result (simulation/run-scenarios {:runner (choose-runner scenarios concurrency options)
                                           :timeout-in-ms step-timeout
                                           :context (:context options)
-                                          :error-file (path-join results-dir "error.log")}
+                                          :error-file (or (:error-file options)
+                                                          (path-join results-dir "error.log"))}
                                          (weighted-scenarios (range concurrency) scenarios)
                                          true)]
     (let [summary (report/create-result-lines start-time

                                           :timeout-in-ms timeout-in-ms
                                           :context context
                                           :requests requests
                                           ;; TODO: make configurable
                                           :error-file (path-join results-dir "error.log")
                                           :duration duration})
        summary (report/create-result-lines simulation
                                            buffer-size

      (println (str "Open " results-dir "/index.html"))
      summary)))

(defn run [simulation {:keys [concurrency root timeout-in-ms context
                              requests duration reporter error-file]
                       :or {concurrency 1
                            root "target/results"
                            timeout-in-ms 5000
